Microscopy system and method

ABSTRACT

A microscopy system method for inspecting a retina of an eye comprises generating an inverted intermediate image of the retina using an ophtalmoscopic lens; detecting a left image of the intermediate image from a left viewing direction and detecting a right image of the intermediate image from a right viewing direction; and displaying an inverted representation of the detected left image to a right eye of a user and displaying an inverted representation of the detected right image to a left eye of the user.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a microscopy system and method. In particular, the invention relates to a surgical microscopy system of the binocular type and a microscopy method for inspecting a retina of an eye.

2. Brief Description of Related Art

From U.S. Pat. No. 4,786,154 there is known a stereo-microscopy system comprising an objective lens for transforming an object-side imaging beam emerging from an object plane of the objective lens into an image-side imaging beam. A left zoom system and a right zoom system are disposed within the image-side imaging beam. The left zoom system picks up a left beam portion of the image-side imaging beam and supplies that portion with an adjustable magnification to a left ocular of the microscopy system. Similarly, the right zoom system picks up a right beam portion of the image-side imaging beam and supplies that portion with an adjustable magnification to a right ocular of the microscopy system. Two semitransparent mirrors are disposed in each of the left and right beam portions in-between of the respective zoom system and ocular. A first of the two mirrors is used to supply light of the respective beam portion to a camera. Images detected by the camera are supplied to a controller for further processing. The controller supplies the processed images to a display, and light generated by the display is superimposed with the respective beam portion by the second semitransparent mirror. When looking into the oculars, the user may perceive a direct image of the object and a superimposed representation generated by the displays.

The two semitransparent mirrors disposed in the beam paths tend to increase the volume and length of the microscopy system.

From EP 1 191 381 A2 there is known a stereo-microscopy system which is configured to be used for surgery at the human eye and to generate a stereo-microscopic image of a retina of the eye. For this purpose, an ophthalmoscopic lens is inserted in a beam path between the objective lens of the microscopy system and the eye under surgery. The ophthalmoscopic lens generates an intermediate image of the retina of the eye in the object plane of the objective lens. The intermediate image is an inverted image, and the microscopy system comprises optics for interchanging the stereo channels of the microscopy system and for inverting each of the stereo-images supplied to oculars of the microscopy system.

Such optics also tends to increase the volume and length of the microscopy system.

SUMMARY OF THE INVENTION

The present invention has been accomplished taking the above problems into consideration.

It is an object of the present invention to provide a stereo-microscopy system of a simplified configuration and which is suitable to be used in combination with an ophthalmoscopic lens.

It is a further object of the present invention to provide an improved microscopy method for inspecting a retina of an eye.

The foregoing objects are accomplished by providing a microscopy system for generating a magnified stereoscopic image of an object. The microscopy system comprises an objective lens for transforming an object-side beam emerging from an object plane of the objective lens into an image-side beam. Left and right cameras are disposed within the image-side beam to be supplied with light of left and right beam portions of the image-side beam for detecting an image of the object from left and right viewing directions, respectively. The microscopy system further comprises left and right displays for generating representations of the object to be viewed by a left and right eyes, respectively, of a user.

A control system of the microscopy system has first and second modes of operation. In the first mode of operation, the controller supplies an inverted representation of the image detected by the left camera to the right display, and supplies an inverted representation of the image detected by the right camera to the left display.

The invention thus provides a simplified microscopy system to be used in combination with an ophthalmoscopic lens and which performs the necessary interchanging of the stereo-channels together with the necessary image inversion. Other than in the conventional system, where the interchanging of the stereo-channels and image inversion is achieved by using complicated optical means, the interchanging of the stereo-channels and image inversion is achieved in the microscopy system according to the present invention by electronic means provided by the controller.

In the second mode of operation, a non-inverted representation of the image detected by the left camera is supplied to the left display, and a non-inverted representation of the image detected by the right camera is supplied to the right display. In the second mode of operation the microscopy system may be used for inspecting an object which is disposed in the object plane of the objective lens. The microscopy system may be switched from the first mode of operation to the second mode of operation, i.e. from an operation involving use of an ophthlamoscopic lens to an operation without involving such ophthalmoscopic lens, by a switching of the control system and without making it necessary to move optical components into the beam path or out of the beam path.

According to an exemplary embodiment of the invention, the left and right displays are comprised in a head mounted display. The user may then freely move relative to the objective lens while viewing the magnified stereoscopic representation of the object. According to a further exemplary embodiment, the left and right displays are mounted on a support such that the user has the choice of viewing the magnified representation of the object through the displays or viewing directly onto the object or some other point of interest.

According to some embodiments of the invention, the microscopy system further comprises a left ocular and a right ocular which are supplied with light of the left and right beam portions such that the user may also perceive a purely optical stereomicroscopic representation of the object by looking into the oculars. In such embodiments, the microscopy system preferably comprises a beam splitter for supplying light of the left and right beam portions to both the respective ocular and the respective camera.

In an exemplary embodiment herein, the inspection, in the second mode of operation for inspecting the object disposed in the object plane without an ophthalmoscopic lens disposed in the beam path, is performed using the optical beam path between the objective lens and the oculars. In the first mode of operation for inspecting the object using the inverting ophthalmoscopic lens, the inspection is performed using the representations generated by the displays and superimposed with a beam path towards the oculars, wherein inverted representations of the images detected by the cameras are supplied while interchanging the stereo-channels.

In a further exemplary embodiment herein, the microscopy system comprises a beam switch having a first switching state in which the supply of the beam portions to the oculars is allowed, and a second switching state in which the supply of the beam portions to the oculars is blocked.

According to an exemplary embodiment of the invention, the operation of the beam splitter is synchronized with a switchable illumination system of the microscopy system, wherein the illumination system has a first illumination state in which an illuminating beam is directed towards the inspected object, and a second illumination state in which an illuminating beam is not directed onto the object. In the first mode of operation of the control system the beam path between the objective lens and the oculars is not blocked, wherein the object is not illuminated in this first mode of operation, however. Thus, the user will not perceive the object through the optical beam path when looking into the oculars in the first mode of operation. He will then perceive the representation generated by the displays, which generate inverted representations of the object while interchanging the stereo-channels. Thus, the user will perceive non-inverted representations of the object with a correct stereo base while using the ophthalmoscopic lens. The two beam portions are permanently supplied to the cameras. The images of the object are substantially only detected in the second mode of operation of the control system since it is only then that the illumination system illuminates the object with the illuminating beam. In this first mode of operation the direct beam path of the two beam portions towards the oculars is blocked such that the user will not perceive the direct optical inverted image with interchanged stereo-channels when looking into the oculars in the second mode of operation. If necessary, the camera, the display or the corresponding controller may comprise a memory for storing the images detected by the cameras during the second mode of operation where the cameras will detect the images. Representations of the stored images will be supplied to the displays during that time where the illuminating beam is not incident on the object. Such memory may not be necessary if a response time of the display is sufficiently low such that the intensity variations caused by the intermittent illumination of the object are not perceived by the user.

Preferably, the switching between the first and second modes of operation is periodically performed at a sufficiently high frequency such that the user will substantially continuously perceive the inverted representations with interchanged stereo-channels of the object.

The invention further provides a microscopy method for inspecting a retina of an eye, the method comprising: generating an inverted intermediate image of the retina; detecting a left image of the intermediate image from a left viewing direction and detecting a right image of the intermediate image from a right viewing direction; and displaying an inverted representation of the detected left image to a right eye of a user and displaying an inverted representation of the detected right image to a left eye of the user.

BRIEF DESCRIPTION OF THE DRAWINGS

The forgoing as well as other advantageous features of the invention will be more apparent from the following detailed description of exemplary embodiments of the invention with reference to the accompanying drawings, wherein:

FIG. 1 schematically shows a stereo-microscopy system which may be used in combination with an ophthalmoscopic lens, according to a first embodiment of the invention;

FIG. 2 schematically shows a stereo-microscopy system which may be used in combination with an ophthalmoscopic lens, according to a second embodiment of the invention; and

FIG. 3 schematically shows a stereo-microscopy system which may be used in combination with an ophthalmoscopic lens, according to a third embodiment of the invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

In the exemplary embodiments described below, components that are alike in function and structure are designated as far as possible by alike reference numerals. Therefore, to understand the features of the individual components of a specific embodiment, the descriptions of other embodiments and of the summary of the invention should be referred to.

FIG. 1 schematically illustrates a microscopy system 1 comprising an objective lens system 3 having plural objective lenses 5 for transforming an object-side imaging beam 9 emerging from an object plane 7 of the objective lens 3 into an image-side imaging beam 11.

A beam splitter arrangement 13 is disposed in the image-side imaging beam 11. The beam splitting arrangement 13 comprises a prism 15 of the Bauernfeind type and having a wedge shaped prism 17 cemented thereon. A splitting of the beam path is generated at an interface 19 of the beam splitting arrangement, wherein a beam path for a main user straightly traverses the interface 19. A pair of zoom system 21 each having plural zoom lenses 23 is disposed in the beam path of the main user downstream of the beam splitter arrangement. Only one of the two zoom systems 21 is visible in FIG. 1 while hiding the other zoom system.

Each of the zoom systems picks up a beam portion 25 of the image-side imaging beam 11 to supply that beam portion 25 to a beam splitting arrangement 27. The beam splitting arrangement 27 comprises a prism 29 of the Bauernfeind type having a first surface 31 facing towards the zoom system 21, wherein the beam portion 25 supplied by zoom system 21 enters prism 29 through the first surface 31. The prism 29 has a second semitransparent surface 33 for splitting the beam path into an ocular beam path 35 and a camera beam path 37, wherein the camera beam path straightly traverses the semitransparent surface 33 and the ocular beam path 35 is reflected from second surface 33. The ocular beam path 35 is then reflected from the first surface 31 of prism 29 by internal total reflection and then emerges from prism 29 by traversing a third surface 39 of prism 29 to enter a body of a tube 41 comprising plural lenses 43 and a beam deflector 45 to supply the ocular beam path to oculars 47. The oculars 47 are pivotable to be adaptable to a distance of the eyes of the user.

The camera beam path 37 traverses the second surface 33 of prism 29 and enters a prism 48 which is joined to prism 29 by cementing. The camera beam path 37 straightly traverses prism 48 and emerges therefrom through a surface 49 to be incident into a camera 51 having a camera adapter optics 53 and a CCD chip 55. Images detected by the CCD chip 55 are read out by a controller 57 to be stored in an archive 59, such as a magnetic tape or other, or to be displayed on a computer display 61 after performing some image processing, if desired. The controller 57 is further configured to supply data to a display 65. The data may comprise the images detected by camera 51, the corresponding image processed images or other data such as data entered by using a keyboard 63. The display 65 comprises a LCD chip 67 and a display optics 69. Light generated by the display 65 enters prism 48 by traversing a surface 71 thereof under such an angle that a beam path 73 of the display is superimposed with the ocular beam path 35 after traversing the second surface 33 of prism 29. When looking into the oculars 47 the user will perceive both the optical image of the object plane 7 supplied by the object-side imaging beam 11 and the corresponding beam portions 25, and the superimposed representations generated by the displays 65.

A beam path 81 reflected by prism 15 of the Bauernfeind type is supplied to oculars 83 for an assistant user to perceive an optical image of object plane 7. A pair of zoom systems 84 and a tube 85 having a similar configuration as zoom system 21 and tube 41 illustrated above are disposed in beam path 81.

FIG. 2 schematically illustrates a microscopy system 1 a comprising an objective lens 3 a having an object plane 7 a. The objective lens 3 a transforms an object-side imaging beam 9 a emerging from an object plane 7 a into an image-side imaging beam 11 a. Two cameras 41 al and 41 ar are disposed in the image-side imaging beam 11 a (the additional character l stands for “left”, and the additional character r stands for “right”). The cameras 51 al and 51 ar each comprise a camera adapter optics 53 al,r and a CCD chip 55 al,r and detect images of the object plane 7 a from left and right viewing directions, respectively. In the embodiment shown in FIG. 2 zoom systems are not disposed in the beam path between the objective lens and the cameras; corresponding zoom systems may be provided, however, for optically changing a magnification of the images detected by cameras 51 al,r.

The microscopy system la is used for inspecting a retina 91 of an eye 93 and comprises an opththalmoscopic lens 94 generating an intermediate image of retina 91 in the object plane 7 a. An example of an ophthalmoscopic lens is disclosed in U.S. Pat. No. 4,728,183. The images detected by cameras 51 al, 51 ar are inverted pseudo-stereoscopic images. This means that the stereo-channels are interchanged and that the left and right and up and down sides of the images are inverted.

The images detected by cameras 55 al, 55 ar are supplied to controller 57 a via data lines 101 l, 101 r, respectively, transformed by electronic image inverters 103 to have a correct orientation, and supplied to a head mounted display 105. The head mounted display comprises a left display 65 l to be viewed with a left eye of the user, and a right display 65 r to be viewed by a right eye of the user. The images detected by camera 55 al are supplied to display 65 r after image inversion, and the images detected by camera 55 ar are supplied to display 65 l after image inversion, such that the user will perceive a correctly oriented representation of the retina 91 with a correct stereo impression.

If the user intends to inspect an object disposed in the object plane 7 a without using the ophthalmoscopic lens 94, he will switch the controller 57 a to a second mode of operation, wherein a corresponding switch 109 is only schematically indicated in FIG. 2. In the second mode of operation the images detected by camera 55 al are supplied to display 65 l without being inverted, and the images detected by camera 55 a are supplied 65 r without being inverted.

FIG. 3 shows a stereo-microscopy system 1 b which can be operated in a first mode of operation for inspecting a retina using an ophthalmoscopic lens and a second mode of operation for inspecting an object without such ophthalmoscopic lens.

The inspection without ophthalmoscopic lens is a direct optical inspection wherein an object-side beam 9 b is transformed into an image-side beam 11 b by an objective lens 3 b. A pair of zoom systems picks out a pair of beam portions 25 b which are finally supplied to respective oculars 47 b. Only one zoom system 21 bl is shown in FIG. 3. The two beam portions 25 b are split by a prism 29 b of the Bauernfeind type. A first portion of the split beams forms an ocular beam path 35 b and is supplied to the oculars 47 b via a tube arrangement 41 b. A second portion of the split beams forms a camera beam path 37 b and is supplied to a pair of cameras 51 b having a CCD chip 55 b, wherein a camera 55 bl detects an image of an object plane from a left viewing direction, and a second camera (not shown in FIG. 3) detects an image of the object plane from a right viewing direction.

The images detected by cameras 55 b are read out by a controller 57 b and supplied to displays 65 b having LCD chips 67 b for displaying the images.

In the first mode of operation where the ophthalmoscopic lens is used for inspection, the images of the displays 67 b are superimposed with the ocular beam paths by a hinged mirror 111 which is disposed in the ocular beam paths 53 b as indicated by solid lines in FIG. 3 b. In this shown position the hinged mirror 111 blocks the light emerging from the object and supplied by the zoom systems 21 b towards the oculars. When looking into the oculars 47 b the user will perceive the images of the representations generated by the displays 67 b wherein the controller 57 b has inverted the images detected by cameras 55 b and has interchanged the stereo-channels. Thus, the user will perceive an image of a retina through an ophthalmoscopic lens (not shown in FIG. 3) with a correct orientation and correct stereoscopic impression.

For inspecting the object without ophthalmoscopic lens, the hinged mirror 111 is rotated by a corresponding actuator (not shown in FIG. 3) under the control of controller 57 b to a position shown in broken lines in FIG. 3. In such position the mirror 111 does not superimpose the light generated by the displays 67 b with the ocular beam path, and the mirror 111 does not block the light emerging from the object and supplied to the oculars 47 b through the objective lens 3 b, the zoom systems 21 b and the beam splitter 29 b. The user may directly inspect the object by pure optical imaging, accordingly.

Also the microscopy system 1 is configured for an inspection involving an ophthalmoscopic lens. For this purpose, the microscopy system 1 comprises an illumination system 121 comprising a light source 123 and a reflector 125 for generating a light beam 127. A collimator 129 is provided for forming light beam 127 to be a collimated beam 131. A further lens group 133 is provided to transform collimated beam 131 into an illuminating beam 135 suitable for illuminating an object field in object plane 7. The illumination system 121 is schematically illustrated in FIG. 1 such that the illuminating beam 135 is obliquely incident on object plane 7. Other embodiments suitable for ophthalmoscopic surgery will use illuminating beams reflected from deflecting mirrors such that the beam is incident onto the object plane under only a small angle relative to the optical axis of the objective lens.

The illuminating system 121 further comprises a chopper 137 having a motor 139 and a chopper wheel 149 having plural chopper blades for alternatingly blocking the illuminating beam 135 and allowing the beam to pass through. A rotating speed and phase of the motor 139 is controlled by controller 57. The object will alternatingly be illuminated and not be illuminated. A beam shutter 141 is disposed in a beam path between the prism 29 of the Bauernfeind type and the tube 41. In a state of the illuminating system 121 where the object is illuminated, the controller switches the light shutter 141 into its light blocking state such that the user will not perceive the optical image of the object when looking into the oculars 47. The cameras 51 will detect an image of the object in such illumination state and the controller 57 will read out those images, invert the images as indicated by inverters 103 in FIG. 2 and supply the inverted images to displays 65 which will display the corresponding images also during those time intervals in which the chopper wheel 49 blocks the illuminating beam 135. At that time, the controller 57 controls the light shutter 141 to be switched into its light transmitting state such that the representations of the object generated by displays 65 have a correct orientation and will be perceived with a correct stereoscopic impression.

Summarized, a microscopy system method for inspecting a retina of an eye comprises generating an inverted intermediate image of the retina using an ophtalmoscopic lens; detecting a left image of the intermediate image from a left viewing direction and detecting a right image of the intermediate image from a right viewing direction; and displaying an inverted representation of the detected left image to a right eye of a user and displaying an inverted representation of the detected right image to a left eye of the user.

The present invention has been described by way of exemplary embodiments to which it is not limited. Variations and modifications will occur to those skilled in the art without departing from the scope of the present invention as recited in the appended claims and equivalents thereof. 

1. A microscopy system for generating a magnified stereoscopic representation of an object, the system comprising: an objective lens for transforming an object-side imaging beam emerging from an object plane of the objective lens into in image-side imaging beam; an ophthalmoscopic lens which is selectively disposable in a beam path between the object and the object plane of the objective lens to generate an inverted image of the object in a region of the object plane; a left camera configured to be supplied with light of a left beam portion of the image-side imaging beam, for detecting an image of the object from a left viewing direction; a right camera configured to be supplied with light of a right beam portion of the image-side imaging beam, for detecting an image of the object from a right viewing direction; a left display for generating a representation of the object to be supplied to a left eye of a user; a right display for generating a representation of the object to be supplied to a right eye of the user; and a controller configured to be operated in a first mode of operation to receive the image detected by the left camera and to supply an inverted representation of the image detected by the left camera to the right display, and to receive the image detected by the right camera and to supply an inverted representation of the image detected by the right camera to the left display.
 2. The microscopy system according to claim 1, wherein the ophthalmoscopic lens is removable from the beam path between the object and the object plane of the objective lens.
 3. The microscopy system according to claim 2, wherein the controller is further configured to operate in a second mode of operation to receive the image detected by the left camera and to supply a non-inverted representation of the image detected by the left camera to the left display, and to receive the image detected by the right camera and to supply a non-inverted representation of the image detected by the right camera to the right display.
 4. The microscopy system according to claim 1, wherein the left display and the right display are provided in a head mounted display.
 5. The microscopy system according to claim 1, further comprising a left ocular, a right ocular, and at least one optical component configured to provide a beam path for supplying light of the left beam portion to the left ocular and supplying light of the right beam portion to the right ocular.
 6. The microscopy system according to claim 5, further comprising a beam splitter for splitting the light of the left beam portion for supply to both the left ocular and the left camera, and for splitting the light of the right beam portion for supply to both the right ocular and the right camera.
 7. The microscopy system according to claim 6, further comprising a beam switch configured to have a first switching state in which the light of the left beam portion is blocked and not supplied to the left ocular and in which the representation generated by the left camera is supplied to the left ocular, and in which the light of the right beam portion is blocked and not supplied to the right ocular and in which the representation generated by the right camera is supplied to the right ocular, and wherein the beam switch is configured to have a second switching state in which the light of the left beam portion is supplied to the left ocular, and the light of the right beam portion is supplied to the right ocular.
 8. The microscopy system according to claim 7, wherein the controller is configured to switch the beam switch into the first switching state in the first mode of operation, and to switch the beam switch into the second switching state in the second mode of operation.
 9. The microscopy system according to claim 5, further comprising a switchable illumination system configured to have a first illuminating state in which an illuminating beam is directed onto the object, and a second illuminating state in which the illuminating beam is not directed onto the object.
 10. The microscopy system according to claim 9, further comprising a beam switch configured to have a first switching state in which the light of the left beam portion is blocked and not supplied to the left ocular and in which the representation generated by the left camera is supplied to the left ocular, and in which the light of the right beam portion is blocked and not supplied to the right ocular and in which the representation generated by the right camera is supplied to the right ocular, and wherein the beam switch is configured to have a second switching state in which the light of the left beam portion is supplied to the left ocular, and the light of the right beam portion is supplied to the right ocular.
 11. The microscopy system according to claim 10, wherein the controller is configured to switch the beam switch into the first switching state and to switch the illumination system into the first illuminating state in the first mode of operation, and to switch the beam switch into the second switching state and to switch the illumination system into the second illuminating state in the second mode of operation.
 12. A microscopy method for inspecting a retina of an eye, the method comprising: generating an inverted intermediate image of the retina; detecting a left image of the intermediate image from a left viewing direction and detecting a right image of the intermediate image from a right viewing direction; and displaying an inverted representation of the detected left image to a right eye of a user and displaying an inverted representation of the detected right image to a left eye of the user.
 13. The microscopy method according to claim 12, wherein the displaying the inverted representation of the detected left image comprises supplying the inverted representation of the detected left image to a right display and wherein the displaying the inverted representation of the detected right image comprises supplying the inverted representation of the detected right image to a left display.
 14. The microscopy method according to claim 12, wherein the inverted intermediate image is temporarily not generated, and further comprising: detecting a left image of the object from a left viewing direction and detecting a right image of the object from a right viewing direction, while the inverted intermediate image is not generated; and displaying a non-inverted representation of the detected left image to the left eye of the user and displaying a non-inverted representation of the detected right image to the right eye of the user.
 15. The microscopy method according to claim 12, further comprising: providing an optical beam path for supplying an optical left image of the object from a left viewing direction to the left eye of the user and for supplying an optical right image of the object from a right viewing direction to the right eye of the user. 